add test directory

Author: jaredly

internal/Something.ml

@@ -2,4 +2,6 @@
 (* we can have ocaml as well as reason sources *)
 let opt = Re.opt
 
-let format = "OCaml"
+let format = "OCaml"
+
+let calculate x = x * 2

tests/jbuild

@@ -0,0 +1,10 @@
+(jbuild_version 1)
+
+(executable
+ ((name test)
+  (libraries (internal))))
+
+(alias 
+ ((name runtest)
+  (deps (test.exe))
+  (action (run ${<}))))

tests/test.re

@@ -0,0 +1,13 @@
+
+let res = Internal.Something.calculate 4;
+let main () => {
+  if (Internal.Something.calculate 4 != 8) {
+    print_endline "Test failure!!";
+    exit 1;
+  } else {
+    print_endline "Tests passed";
+    exit 0;
+  }
+};
+
+main();